1. Field of the Invention
The present invention relates to an overtube and an endoscopic surgical device, and particularly, to an overtube and an endoscopic surgical device that has a function of cleaning an observation window of an endoscope.
2. Description of the Related Art
In recent years, since invasion to a patient is small compared to surgery in which a laparotomy, a thoracotomy, or the like, is performed, endoscopic surgery using endoscopes (hard endoscopes), such as a laparoscope, has been widely performed. In endoscopic surgery, a plurality of holes are made in a patient's body wall, an endoscope is inserted into a body cavity from one hole of these and a treatment tool is inserted into the body cavity from another hole. Then, treatment of a living body tissue is performed with the treatment tool while observing the living body tissue within the body cavity with the endoscope.
Generally, in endoscopic surgery, one or a plurality of treatment tools are used simultaneously with the endoscope. Therefore, since it is difficult for one surgeon to simultaneously operate the endoscope and the plurality of treatment tools, for example, a task, such as operating a treatment tool that the surgeon holds with his/her hands while making an assistant called an endoscopic technician operate the endoscope is normally performed.
Additionally, in endoscopic surgery, an overtube called a trocar, or the like is used. The overtube consists of a cylindrical body inserted into a body wall, and is a guide instrument for introducing instruments, such as the endoscope and a treatment tool, into the body cavity.
Meanwhile, a distal end of an insertion part of the endoscope is provided with an observation window, and observation within the body cavity is performed via the observation window. Therefore, although it is always necessary to keep the observation window clean, foreign matter (mucus, fats and oils, tissue pieces, or the like) may adhere to the distal end of the insertion part of the endoscope introduced into the body cavity via the overtube. In this case, since an image of a site to be treated and the treatment tool becomes unclear, operations such as a surgeon first extracting the insertion part of the endoscope from the overtube and then wiping the observation window are required. Therefore, surgery time may be lengthened or a surgeon may miss a site to be treated, which causes degradation in surgical efficiency.
Additionally, there are also many situations where foreign matter adheres to the inside of the overtube, and even if the observation window is cleaned after the insertion part of the endoscope is first extracted from the overtube, the foreign matter may adhere to the observation window when the insertion part of the endoscope is inserted again into the overtube.
As opposed to such a problem, for example, JP2010-17559A discloses that the cylindrical body (sheath) that covers the insertion part (observation instrument for surgery) of the endoscope has a function of cleaning the observation window (observation element). A fluid supply and discharge port through which cleaning water is allowed to be supplied to and suctioned from a distal end side (body cavity side) of an insertion passage through which the insertion part of the endoscope is inserted is provided inside this cylindrical body. A distal end surface of the insertion part of the endoscope is positioned in the vicinity of the fluid supply and discharge port, and when cleaning water is supplied to or suctioned from the fluid supply and discharge port, cleaning of the observation window is performed.